Wood flooring



Patented May 2, 1933 UNITED STATES FREDERICK PETER POTVIN, OlF TORONTO, ONTARIO, CANADA.

WOOD

FLOORING 'Application led December 22, 1931, Serial No. 582,559, and in Canada December 29, 1980.

This invention relates to Viooring, and my object is to provide means for securely holding together the individual strips in a block. Further objects are to provide strongly constructed tongues which will not split when the strips or blocks are nailed to the floor; to provide space for accommodating excess mastic when the floor is laid on cement; and to provide means for absorbing expansion of the hardwood strips due to moisture.

l attain these objects by the use of a U- shaped metal spline which is inserted in a groove or grooves in one or more of the edges of the strips or blocks, preferably transversely across the ends of the strips to hold them together; by providing dovetailed grooves on the under side of each block to take up excess mastic and form a key to retain the block firmly in its cement base; and by providing concave sides tothe strips forming the block, whereby provision is made for expansion of each individual strip in the block without expansion of the block itself.

My invention is hereinafter more specifically described and is illustrated in the accompanying drawing in which Fig. l is a perspective view taken diago; nally of a block;

Fig. 2 a plan view of the under side of a block, partly broken away;

Fig. 3 a cross section of a block;

Fig. 4 a side elevation, partly in section, of two blocks laid together;

Fig. 5 a side elevation partly in section of a modified form of-block; and

Fig. 6 a cross section of the block shown in Fig. 5. p Y

In the drawing like numerals of reference indicate corresponding parts in the different gures. n

This invention relates chiefly to blocks of `iooring 1,'composed of a plurality of strips 2, which are held together by U-shaped metal tongues 3, 3, the arms of which 'are driven into and frictionally engage in parallel saw kerfs or slots 4 extending transversely across -the ends of the strips 2. One tongue 3 is provided at each opposite end of the block.

50 Along the outer edge of each outer strip 2 of the block l, is formed a groove 5 adapted to receive one of the metal tongues 3. Thus each block is provided at two opposite sides with tongues and at the other two opposite sides with grooves so that they may be fitted together with the strips running in alternate directions to form a block or parquetry floorgEach strip in each blockniay be connected to the adjoining strip by a tongue and groove connection, but this is unnecessary since the metal tongues 3, 3, securely hold the strips together in block form.

This flooring is largely used on a concrete base. In laying the flooring the under side of each block is dipped in a mastic or plastic cement and the block is then laid on the cement iioor and tapped into close contact and tongue and groove connection with adjoining blocks which have already been laid. To take up excess mastic and permit the floor to rest firmly and evenly on the cement base, parallel dovet-ailed grooves 6 are formed in the base of each block. rlhese grooves 6 run longitudinally of the strips 2 and are formedy 75 by cutting V-shaped grooves from the edges of the under side of each strip, so that when the strips are placed together to form blocks the V-shaped grooves of adjacent strips combine to form the dovetailed groove 6. Mastic which enters this groove hardens and forms a key which holds the block firmly in position in the cement base.

When flooring is laid on cement there is frequently considerable moisture present 85 which is absorbed by the wood and causes swelling to occur. Unless some means of taking up this swelling is provided the floor will buckle up. It has been proposed to apply a waterproof solution'to the blocks t0 prevent` 90- the absorption of moisture, but so far no solution'has been discovered which will satisfac-n torily exclude all moisture and prevent swelling. l overcome this difficulty by providing the adjacent sides of each strip with shallow concave grooves 7, so that when the block is made up while the strips are in close contact adjacent their top and bottom surfaces there is a spaceor cavity between each strip 2 which 'takes up any swelling which may occur. 100

When swelling occurs lthe strips at their contacting edges are compressed together forming a very tight joint, while the main part of the expansion is taken up by grooves 7 so that while each strip in each block may expand the block as a whole does not expand with moisture. It is thus possible to lay the blocks close together and to lay the floor close up to the wall without any allowance for expansion, since all expansion will be absorbed within each block. The edges of the strips are preferably in contact at the bottom as well as the top, because if space were left at the bottom mastic might enter and fill up the spaces and also swelling of the strips from moisture might tend to cause them to buckle up owing to the greater pressure on the upper surface. To prevent chipping of the surface of the block, I prefer to make the edges parallel for about f to 1/8 adjacent the upper and lower surfaces of the block above and below the concave groove 7 The modified construction shown in Fig. 5 is chiefly designed for use when the flooring is being laid on a wood base to which it is to be nailed, although it may also be used when the flooring is laid on cement. 4The drawing shows a nail 8 as it would pass throu h the block at an angle from a. point just a ove the tongue 3. To permit of the passage of the nail the upper arm is cut away or made shorter than the lower arm of the tongue 3, and instead of a pair of slots 4, only one is provided, the lower longer armvof the tongue 3 being frictionally engaged therein. This construction is superior to a construction in which an ordinarywooden tongue or spline is used since the metal tongue will not split and absolutely prevents splitting of the strip itself. Y

Fig. 6 shows the grooves 7 of a slightly modified form or shape from the form shown in Fig. 3. This shape is preferred since it provides greater space for expansion adjacent the top and bottom of the groove. With the more gradual curve of Fig. 3 the pressure might become so great' adjacent the ends' of the groove that further expansion centrally of the groovefwould be prevented.

Although I have described my invention in connection with block flooring, where it is particularly useful, it is apparentithat my improved tongue may be used to advantage to replace the usual wooden tongue on ordinary strips of flooring.

Wnat I claim as my invention is:

l. A flooring block comprising a plurality of -strips of wood, provided with two parallel slots extending transversely of the block across the ends of the strips; U-shaped metal tongues having their arm frictionally engaged in said slots; and grooves extending longitudinally of the block in the outer edge of each outer strip, into which the metal tongues of adjacent blocks are adapted to lit to form tongue and groove connections.

2. A flooring block comprising a plurality of strips of wood, each strip having concave sides abutting the sides of the adjacent strip, thesidesbeing substantially parallel adjacent the upper and lower surfaces of the block above and below the concavity; U-shaped metal tongues extending transversely ofthe block across the ends of the strips; and grooves extending longitudinally of the block in the outer edge of each outer strip, into which the metal tongues of adjacent blocks are adaptedto fit to form tongue and groove connections.

3. A flooring block comprising a plurality of strips of wood; U-shaped metal tongues extending transversely of the block across the ends of the strips; grooves extending lon. gitudinally of the block in the outer edge of each. outer strip, into which the metal tongues of adjacent blocks are adapted to fit to form tongue and groove connections; and the edges of the underside of each strip having V-shaped grooves cut therein which combine with similar grooves in the adjacent strip to form longitudinal dovetails on the under surface of the block.

4. A flooring block comprising a plurality of strips of wood, each strip having concave sides abutting the sides of the adjacent strip, and means for retaining the strips in adjacent contacting relationship, the concavities being adapted to take up expansion of the block due to moisture so that the outside dimensions of the block are substantially in` variable.

5. A flooring block comprising a plurality of strips of wood, each strip having concave sides abutting the sides of the adjacent strip, and a spllne or tongue extending transversely across the ends of the strips to retain the strips in adjacent contactingrelationship, the concavlties being adapted to take up ex pansion of the block due to moisture so thatl the outside dimensions of the block are substantially invariable.

6. A flooring block constructed as set forth in claim 5 in which the sides ofthe strips 'adjacent the upper and lower surfaces of the block above and below the stantially parallel.

7. A flooring block having the outer face of an edge slotted substantially parallel to concavity are subtheupper and lower surfaces of the block, in-

combination with a projecting metal 'tongue of U-form in cross section having its arms in spaced relationship, the said tongue having an arm frictionally engaged in the slotted edge of the block and said tongue extending outwardly substantially parallel with the surfaces of the blocky for engagement in a groove in an adjacent block.

8. A flooring block having the outer face of an edge slotted substantially parallel to the u per and lower surfaces of the block, in

combination with a projecting metal tongue of U-form in cross section having its arms parallel and in spaced relationsh1p, the said tongue having an armrictionally engaged in the slotted edge of the block and said tongue extending outwardly substantially parallel with the surfaces of the block for engagement in a groove in an adjacent block.

9. A flooring block having parallel slots in the outer face of an edge substantially parallel to the upper and lower surfaces of the block, in combination with a projecting metal tongue of U-form in cross section having its arms parallel and in spaced relationship, the said tongue having both arms frictionally engaged in said slots.

10. A flooring block having the outer face of an edge slotted substantially parallel to the upper and lower surfaces of the block in combination with a projecting metal tongue of U-form in cross section having its arms in spaced relationship, the'said tongue having one of its arms frictionally engaged in the slotted edge of the block, and the edge of the other arm substantially abutting the edge of the block but not received therein, the said tongue extending outwardly substantially parallel with the surfaces of the block for engagement in a groove in an adjacent block.

11. A flooring block comprising a plurality of strips of wood, said block being slotted transversely across the ends of the said strips and substantially parallel to the upper and lower surfaces of the block, in combination with a projecting metal tongue of Ufform in cross section having its arms in spaced relationship, the said tongue having an arm frictionally engaged in the slotted edge of the block and said tongue extending outwardly substantially parallel with the surfaces of the block for engagement in a groove in an adjacent block. c

12. A flooring-block comprising a plurality of strips of wood, the edges of each strip being concaved and engaging the adjacent edge of the adjacent strip only near the upper and lower surfaces of the block, and a spline or tongue 'extending transversely across the strips to retain the strips in adjacent contacting relationship., the concaviti being adapted to take up expansion of the block due to moisture so that the outside dimensions of the block are substantially invariable.

Signed at Toronto, Canada, this 28th day of July, 1931.

. F. l?. PUTVIN. 

